Fatty acid condensation products and process of preparation



United States Patent ACID CONDENSATIGN PRODUCTS AND PROCESS OFPREPARATION Johannes Donatus Von Milmsch-Buchberg, Hamburg- Harburg,Germany, assignor to Lever Brothers Company, New York, N.Y., acorporation of Maine No Drawing. Application November 25, 1955 SerialNo. 549,173

Claims priority, application Great Britain November 30, 1954 10 Claims.(Cl. 260-3435) This invention relates to novel-condensation products,more particularly to condensation products obtained by the treatment offatty acids which are useful in industrial compositions. When thestarting materials are unsaturated the resulting products areparticularly useful as drying compositions in paints, varnishes, coreoils, linoleum and similar products for partly or wholly replacingdrying oils. When the starting materials are saturated the resultingproducts are useful, for example, as quenching oils or plasticizers.

It has now been found that novel fatty condensation products areobtained by heating non-hydroxylated fatty acids or mixtures containinga substantial amount of nonhydroxylated fatty acids, in the presence ofa small amount of a catalyst, to a temperature between 220 and 330 C.,with removal of the water formed in the reaction until the productcontains a substantial amount of unsaponifiable matter having a meanmolecular weight in accordance with that calculated for a condensationproduct of at least three molecules of fatty acid. Temperatures ofbetween 250 and 300 C. are preferred.

Heating should be carried out under vacuum.

If the reaction is effected under high vacuum the reaction temperaturemay not at once attain the range 220-330 C. since the mixture in thefirst stage of the reaction may boil at a lower temperature than 220 C.,fatty acids passing into the vapour phase together with volatilereaction products. As the reaction proceeds the concentration of fattyacids.in the mixture is reducedv and the boiling point of the mixtureincreases, so that the temperature can gradually be raised.

In view of the evaporation of the fatty acids which takes place duringthe reaction, heating is preferably carried out while refluxing thefatty acids and higher boiling compounds. In this way a greater part ofthe starting material may be converted into the final condensationproduct.

The starting material may contain other constituents such as, forexample, mono-, dior tri-glycerides, or resin acids. In this case themixture should contain a substantial or, preferably, a major amount offatty acids. Such other constituents have a tendency to slow down thedesired reaction and too great a proportion should be avoided. Even whenthey possess sufficient drying properties by themselves or develop themon heating, the amount of additional constituents should not exceed theamount of fatty acids by weight.

Fatty acids for use according to the invention should preferably havethe formula where R is a hydrocarbon group, preferably a :long saturatedhydrocarbon chain, which is preferably unsubstituted. The fatty acidsmust not contain hydroxyl groups in the hydrocarbon chain. It ispreferred that R is an unsaturated alkyl group, preferably of a chainlength of from 9 to 25 carbon atoms, most preferably of a chain lengthof from 17 to 21 carbon atoms.

boric oxide.

the proportion of unsaponifiable matter that can be ob-:

tained depend to some degree on the type of fatty acids which are usedas a starting material. Thus, with fatty acids which have a relativelylow iodine value heating can be carried out at high temperatures for along time, and highv proportions of unsaponifiable matter, e.g. tonearly can be obtained. With fatty acids of high iodine value, forexample over 150, however, heating may have to be discontinued earlier,since gelation may take place and the proportion of unsaponifiablematter may then be lower, e.g. 40-60%. For the same reason in some casesit is preferred to mix fatty acids of different types before they arereacted to enable highly unsaturated acids to be more completelycondensed in one operation.

.With mixtures of fatty acids containing individual acids of differenttypes, it may be advisable to fractionate the original mixture, e.g. bydistillation, or to distill off the mostvolatile and less unsaturatedacids during the condensation reaction (the reflux column beingmaintained at an appropriate high temperature for the purpose) so as toobtain a better drying product.

The fatty acids used as starting materials may in some cases withadvantage be purified according to the usual methods.

The catalystused in the processes of the invention may be anoxygen-containing boron compound. Preferred inorganic boron compoundsare boric acid and alkali pentaborates, preferably ammonium pentaborate,may also be used with advantage. Borax, however, has only a slightactivity as a catalyst. with oxidizing properties are not preferred.

Preferred organic boron compounds are the esters of boric acid, such asboric acid trimethyl ester, boric acid triethyl ester, boric acidmannitol ester, the mixed anhydride of boric acid and acetic acid or themixed anhydride of boric acid and higher fatty acids as obtained, for,example, from a fatty oil such as groundnut oil.

The amount of catalyst may vary widely, for example, between 0.1 and 10%by weight of the starting material. An amount of catalyst of from 26%,by weight is in general preferred.

The process is preferably carried out in a stainless steel reactionvessel provided with a reflux column. The latter may be either heated orcooled, so as to reflux the fatty acids and other higher boilingproducts and to distil otf reaction water and other volatile productsand gases. The water and other volatile products. may be condensed in acooled trap together with any entrained higher boiling products.

The mixture in the vessel is heated to temperatures between 220 and 330C. It is desirable to keep the reaction mixture at temperatures between250 and 300 C- for at least the latter part of the reaction.

The catalyst may be mixed with the starting material or added during theheating in the reaction vessel, or it can be placed in the column.

The reflux column may be packed, for example, with helices, Raschigrings or the like. The reflux column may also be regulated in such a waythat part of'the fatty acids is alowed to distill ofi. 7

After heating, any unchanged fatty acid in the reaction Boron salts,such as, for example','the

Boron compounds mixture may be extracted with a suitable solvent, forexample alcohol. Alternatively, the reaction mixture may be distilledunder vacuum to remove unchanged fatty acid. The residue after solventtreatment or distillation is the desired product. Preferably thereaction mixture is filtered, washed with hot water to remove thecatalyst and dried under vacuum before or after solvent treatment ordistillation.

The distillate or the alcohol extract obtained according to theprocesses of the invention may be re-used for a further reaction sinceit consists substantially of unchanged starting material. it thereaction is allowed to proceed to a stage where only a small proportionof unchanged starting material is contained in the reaction mixturethere may be no need to remove these starting materials.

The residue obtained under the reaction conditions described forms themain product. When the starting material contains unsaturated fattyacids the product shows better drying properties than the correspondingtriglycerides, decreased volatility and increased viscosity whencompared with the fatty acids forming the starting material. The changesin these properties become more evident with increased time ortemperature of heating. The analytical figures show the formation of asubstantial proportion of unsaponifiable matter which is different fromknown fatty ketones. it has been found that this unsaponifiable matteris mainly responsible for the good drying properties and, when isolated,shows outstanding film forming properties.

The invention also includes the novel condensation products obtained bythese processes as such or mixed with unchanged fatty acids.

The condensation products of the invention are characterised by asubstantial amount, preferably at least 40%, of unsaponifiable matter, alow acid and saponification value, an increased iodine value accordingto Wijs as compared to the starting material, and a high mean molecularweight. The mean molecular weight of the unsaponifiable portion isroughly in accordance with, or higher than, the calculated molecularweight of a theoretical condensation product of three molecules of fattyacid. The condensation products have drying properties when the iodinevalue (determined according to Wijs method) is 100 or higher. Thecondensation products have a molecular structure which contains at leastthree alkyl chains. Preferred products are those in which the alkylchains are those of unsaturated acids derived from fatty oils.

The invention also includes the use of the above mentioned productshaving an iodine value (determined by Wijs method) of 100 or higher, toreplace drying materials, such as drying oils, oleo resinous varnishesor alkyd resins in the paint, varnish, linoleum and allied industries.

The new products may be mixed with the usual siccatives based on cobalt,lead or manganese and may be diluted with turpentine, mineral spiritsand/ or other volatile solvents to the desired viscosity.

As an example of the use of the condensation products according to theinvention, a product obtained from soya bean oil fatty acids accordingto the process described above, in a yield of 75.4%, had an acid valueof 8.6, a saponification value of 44.2, an iodine value of 175.3(determined according to Wijs method) and contained 82.5% unsaponifiablematter. It behaved as follows when tested as a paint vehicle or clearvarnish. The viscosity was 37 poises/20 C. as in the case of a thinstand oil. A product to replace linseed oil was obtained by mixing 57grams of the new condensation product with 33 grams of a 1:1 mixture ofturpentine and mineral spirits. To replace on oleo resinous varnish amixture of 90 grams of the condensation product with grams of the 1:1mixture of turpentine and mineral spirits was prepared. Smallproportions of siccatives were sufficient to obtain shorter drying timesthan those of a good quality boiled linseed oil. With 0.1% cobaltcalculated on the condensation products, for example, 240 minutes wererequired for a film to be dry to the touch and 300 minutes for it to dryhard. The increase in weight upon drying in air for the undilutedcondensation product was higher than that for linseed stand oil of thesame viscosity, showing high ailinity for oxygen, though the product wasobtained from soya bean oil fatty acids having an iodine value muchbelow that of linseed oil. The hardness of the film was tested accordingto Swards method and was found to be substantially higher than that ofboiled linseed oil and as high as that of a maleic resin varnish of 30gallon oil length. The film was more resistant to.

water and dilute sulphuric acid than films of linseed oil and many oleoresinous varnishes.

Zinc white enamels prepared from the condensation products showed nosigns of livering.

In the case of poor drying oils such as herring oil, cotton oil,groundnut oil or rapeseedoil, even if the more saturated component acidswere removed and the remaining unsaturated acids reconverted intotriglycerides, the resulting products would have weaker dryingproperties than the products of the invention made from correspondingacids. The film formed by the product ob tained from linoleic acid as inExample 4 below is harder than the film from any linoleic acid glyeerideand its hardness approaches that of a linolenic acid glyceride.

The invention will now be illustrated by the following examples. In theexamples the temperatures quoted are those of the metal bath surroundingthe reaction vessel. The temperature within the reaction mixture waslower, by about 20 and 30 C. during the initial stages and by about 10C. during the final stages of the reaction.

Example 1 grams fatty acids obtained from Norwegian herring oil by theTwitchell process (acid number of the herring oil acids: 182.7; iodinevalue: 132.7) and 2.75 grams crystalline boric acid were introduced intoa 250 ccs. flask above which a fractionating column was verticallymounted. The column was connected to a vacuum pump through an air-cooledcondenser mounted parallel to the fractionating column and a receptionflask was provided at the bottom of the condenser. The fractionatingcolumn was provided with a packing consisting of stainless steel helicesor glass Raschig rings.

After evacuation of the apparatus to about 2-3 mm. Hg the flask wasslowly heated in a metal bath until the bath temperature was 290 C. Theheating was carried out for 60 minutes until the bath temperature was210 C. Heating was further continued for a further minutes to raise thebath temperature from 210 to 290 C. The bath was maintained at 290 C.for 3 hours. The fractionating column was heated to about C. byelectrical resistance heating. At bath temperatures of from about 210 C.upwards some material commenced to distill olf into the receiving fiask.Condensation of material passing into the fractionating column commencedat a lower bath temperature. After the heating had been continued for 3hours at 290 C. the reaction mixture was allowed to cool. 31.3 grams offatty acids and some water and low boiling decomposition products weredistilled off while 64.4 grams remained in the reaction vessel. Thesolid boric acid contained therein was filtered while the residue wasstill warm. Some material adhered to the packing of the reflux columnand was recovered by extraction with petroleum spirit. The viscousresidue which had an acid number of 10 and contained 81.3%unsaponifiable matter was thinned with petroleum spirit. 0.3% Pb and0.066% Mn were added in the form of naphthenate driers to act assiccatives. When exposed to the air in a thin layer the varnish soprepared dried to a non-tacky filmin less than one day. in a similartest but with only 0.3% by weight of boric acid a larger fraction wasdistilled off so that only about 38% of residue remained in'the reactionvessel. This residue had an acid number of 16.5 and dried aftersiccativation in 6 hours to a non-tacky and hard film.

The fatty acids of pilchard oil, sardine oil and whale oil when treatedaccording to the procedure of this example gave varying quantities (50to 80%) of residue in the form of oily liquids with good dryingproperties.

Example 2 110 grams herring oil fatty acids (acid number: 182, iodinevalue: 142.7) and 6.6 grams of ammonium pentaborate were heated in theapparatus of Example 1 for 60 minutes to a bath temperature of 210 C.,then in 150 minutes to a bath temperature of 290 C. and finally for 60minutes at a bath temperature of 290 C. After cooling 55.5 grams ofresidue which had the consistency of a highly viscous stand-oil waspresent in the reaction vessel.

The residue after dilution with petroleum spirit was filtered to removethe solid catalyst and washed with hot water to remove dissolved boricacid compounds. When the resultant product was treated as described inExample 1 a composition with good drying properties was obtained. A thinfilm of this composition under normal conditions of temperature andlight was dry to the touch in 3 /2 hours and almost non-tacky after 24hours.

- Example 3 Commercial distilled linseed fatty acids (iodine number:165) were slowly heated in the apparatus of Example 1 together with 6%by weight of boric acid until the bath temperature was up to 290 C. Theheating was continued until about 25% of the original material distilledoff as water (about 7%) and fatty acids (about 18%). The residue afterthe addition of siccatives and thinning dried in 3 /2 hours to apractically non-tacky and colourless film and was suitable for replacingboiled linseed oil in the preparation of paints or for use as a clearvarnish.

In a similar experiment samples were taken during the heating of thebatch at bath temperatures of 215, 245, 260, 275 and 290 C. The iodinenumbers of these samples were 167.2; 177.8; 179.9; 179.7 and 190.5 andthe refractive indices were 1.4674; 1.4700; 1.4730; 1.4793 and 1.4905respectively. The last sample had a viscosity of 3.4 poise while theprevious one had only 0.9.poise. Most of the distillate of lower iodinenumber was given off during the early part of the heating and thisaccounted for the rise of iodinevalue of the residue up to about 180.After further heating at a bath temperature ,of 290 C. for about l hourthe residue had gelled. Such gels can find useful application in thevarnish and related industries, e.g. in the preparation of linoleum andcertain paints.

Example 4 -of unsaponifiable matter with a molecular weight of about 900determined according to'Mattiello, Protective and Decorative Coatings,part V, pp. 194-195 (1947). It was largely insoluble in ethyl alcohol,acetone and acetic acid but was soluble in aliphatic and aromatichydrocarbons such as petroleum spirits or-benzene.

The product showed a remarkable increase in iodine number.

the Woburn method, while the product after heating had an iodine numberof 211 according to the Wijs method .and of 234 according to the Woburnmethod, un-

The concentrate before heating had an iodine number of 180 according toboth the Wijs method and were treated in a round-bottom flask. Thefractiona-' saponifiable part of the product (73.4%) showed a stillhigher iodine number, viz. 224 according to the Wijs method and 250according to the Woburn method and a diene number according to theEllis-J ones method of 10.3.

The unsaponifiable portion of the residue obtained by solvent extractionafter saponification had still better drying properties than the productas a whole, drying after addition of siccatives and on thinning to avery hard film equalling china wood oil in hardness and with good waterand alkali resistance.

The fatty distillate which had collected in the receiver and amounted toabout 22% by weight of the material consisted largely of unchangedalthough contaminated linoleic acid and could be used again. It had anacid number of 143.0, a saponification number of 190.6 and an iodinenumber of 1708. About 6% ofwater had collected in a chilled trap in thevacuum'line.

Example 5 110 grams of cottonseedfatty acids obtained by the commercialdistillation of the cotton-soapstock fatty acids tion column was mountedthereon and provided with the packing as described in Example 1. It alsocontained 6.6 grams of boric acid in the form of pieces obtained byapplying a high pressure to a slurry of finely pulverized crystallineboric acid and a small amount of water in a tablet press and afterwardsdrying at about 70 C. in an oven. After evacuation of the apparatus thereaction vessel was heated as in Example 2. A residue of 47 gramsremained, which after the addition of thinner and 'driers dried in 3 /2hours and yielded a hard, elastic and non-tacky film of good surfacecoating properties.

Example 6 110 grams of oleic acid of 97% purity containing 2 to 3% ofsaturated fatty acids were treated with 6.6

grams of boric acid, which had been distributed in the reflux column asin Example 5. The times and temperatures were as described in Example 2.In addition to 6.4 grams of a fatty acid-distillate with an iodinenumber of 52, consisting mainly of a mixture of oleic and palmiticacids, 7.7 grams of an aqueous distillate were collected. The bulk ofthe material which remained in the flask was washed with hot water toremove dissolved boron compounds. After being thus purified, the residuehad a refractive index of 1.4776, an acid number of 58.1, asaponification number of 85.6, an iodine value of 132.9, and a meanmolecular weight of 661 as opposed to the values for the oleic acidwhich were refractive index: 1.4580, acid number: 198.5, saponificationnumber: 199.3 and iodine number 88.0. Although the oleic acid had beenfree of unsaponifiable matter, the residue contained 44.7%unsaponifiable matter. The residue was soluble in ether and petroleumspirit but insoluble in alcohol and acetic acid. There was an overallweight loss of about 2 /2 of the starting material due to gaseousdecomposition products.

Example 7 110 grams of groundnut oil fatty acids (acid number: 197.6;iodine number 98.7) were heated under vacuum in a flask fitted with acolumn containing Raschig rings was raised to 290 C. and held at thistemperature for 1 hour. Owing to the use of the reflux condenser, therewas no distillate other than an aqueous fraction of about 8 grams whichwas condensed in a chilled trap in the vacuum line. The yield of residuewas about including the samples which had been taken from time to timeto 'follow the rise in iodine number and the drop in acid value causedby the increase in unsaponifiable content. The iodine value of theresidue at the end of the experiment was 123.8, its acid value 70.6. Itcontained 20.6% of a fatty acid fraction (iodine number 9.4, acid number175.5) which could be removed by heating under vacuum at 290 C. for onehour, the remainder, which possessed good drying properties, beingpolymeric and non-volatile under these conditions. A similar result wasobtained when pieces of fused boric oxide about the size of peas weredistributed among the packing of the fractionating column.

Example 8 A mixture of neutral oil and free fatty acids obtained duringalkali-refining of rapeseed oil with an acid number of 112 and iodinenumber of 126.8 was treated with 6% of boric acid in the apparatus andmanner described in Example 2. The residue, 77% by weight of theoriginal fatty compound, was a viscous oil with an iodine value of146.1. After addition of thinner and metal driers a film after dryingfor 19 hours exhibited only a slight tackiness.

Example 9 20 kilograms of refined sunflower soapstock fatty acids havingan acid value of 160, a saponification value of 196, and an iodine valueof 127, together with 0.5 kilogram of technically pure boric acid wereheated under a vacuum of 15 to 25 nuns. mercury in a stainless steelapparatus such as is used in manufacturing stand oil and alkyd resins.This apparatus consisted of a gas-heated 50 litre boiler including astirring device and a vacuum sample taker and a reflux cooler mounted onthe boiler and connected to a tubular cooler slanting towards thereceiver. The heating was carried out over 3 hours until the temperaturewas raised to 260 C., continued for a further 4 /2 hours to raise thetemperature to 290 C., and then for a further 4 hours at 290 C. Duringthis time 5.5 kilograms of fatty acid and 0.8 kilogram of watercollected in the receiver.

The remaining residue weighing 13.7 kilograms was repeatedly washed withboiling water and subsequently dried under vacuum at 100 C. and filteredon a filter press. The residue then showed the following characteristics7 Acid value 7.5.

Saponification value -2 86.

Iodine value (Wijs) 143.

Unsaponifiable matter 32%.

Viscosity 165 poises at 20 C.

After the addition of 0.3% lead and 0.02% manganese as naphthenates theresidue dried to the touch in 90 minutes and to completion in 150minutes to give a good water-resisting varnish-like film.

Example 10 In the apparatus described in Example 9, 20 kilograms of afraction obtained from soya bean oil fatty acids (acid value 203.5,saponification value 206.3, iodine value according to Wijs 140.2,unsaponifiable matter 2.8%) and 0.4 kilogram technical boric acid wereheated under a vacuum of 13-20 mrn. to 260 C. within 10 hours and to 290C. in 2 further hours. The fatty acids distilled off during this heatingwere continuously fed back to the reaction kettle. Then the heating wascontinued for 4 hours at a temperature between 260 and 290 (3., duringwhich time, however, the distillate obtained was collected in thereceiver. In this way 0.6 kilogram of a fatty acid distillate and 17.4kilograms of a residue having the character of a stand oil wereobtained. After the residue had cooled down to about 100 C. the boricacid still contained in the residue was removed by repeated boiling witha few kilograms of water and removal of the washing-water. The residuehad a viscosity of 194 poises at C., an acid value of 7.3, asaponification value of 17.9, an iodine value according to Wijs of154.1, and contained 86% of unsaponifiable matter.

After the addition of a lead/manganese naphthenate siccative (0.3% leadand 0.02% manganese) and diluting with a mixture of turpentine andmineral spirits 1:1) to the consistency of a varnish, a product withgood drying properties and useful for the preparation of paints wasobtained. A film of this product was dry to the touch in about 5 hoursand completely dry in 7 /2 hours.

Example 11 20 kilograms distilled tall oil fatty acids with acid value194.3, sapo'nification value 196.9, iodine value according to Wijs131.5, resin content 2%, and 0.4 kilogram technical grade boric acid areheated, with mechanical stirring, over two hours to 230 C. in theapparatus described in Example 10 under a vacuum of 412 mm. mercury.Heating was then carried out for a further 10 hours to 260 C. and thencarried out for 14 hours in the range 260 to 290 C. The fatty acidsdistilling on were reintroduced into the kettle. Towards the end of thereaction only slight amounts of fatty acids were distilling otf. Aftercompletion of the heating 17.5 kilograms of residue were obtained andwashed five times, with 20 kilograms hot water each time, until theboric acid had been removed. The residue was then dried in vacuum andfiltered in a filter press. The product thus obtained showed thefollowing characteristics:

Acid value 6.0.

Saponification value 13.2.

Iodine value (Wijs) 155.9. Unsaponifiable matter 92.1%.

Viscosity 91.5 poises at 20 C.

After addition of 0.3% lead and 0.02% manganese in the form ofnaphthenates as driers and thinning with mineral spirit to a viscosityof 1.5 poises at 20 C. a film of this product was dry to the touch in 6hours and completely dry in 8 hours.

It should be noted that the temperatures given in Examples 911inclusive, are the temperatures of the reaction mixtures, but not bathtemperatures.

I claim:

1. A process for preparing condensation products which comprises heatingan acid of the formula R.C0.0H where R is an unsubstituted long chainhydrocarbon radical, at a temperature of 220 to 330 C. in the presenceof a catalyst selected from the group consisting of boric acid, boricoxide, ammonium pentaborate, trimethyl borate, triethyl borate, mannitolborate and the mixed anhydrides of boric acid and fatty acid, until thereaction mixture contains at least 32% by weight of unsaponifiablematter having a mean molecular weight at least three times that of saidacid, the heating being carried out under such conditions that waterliberated during the reaction is removed from the reaction zone as it isformed but the loss of the major part of the acid is avoided.

2. A process for preparing condensation products which comprises heatingan acid of the formula R.C0.0H where R is an unsubstituted long chainhydrocarbon radical, at a temperature of 220 to 330 C. in the presenceof a catalyst selected from the group consisting of boric acid, boricoxide, ammonium pentaborate, trimethyl borate, triethyl borate, mannitolborate and the mixed anhydrides of boric acid and fatty acid, until thereaction mixture contains at least 32% by weight of unsaponifiablematter having a mean molecular weight at least three times that of saidacid, the heating being carried out under such conditions that waterliberated during the reaction is removed from the reaction zone as it isformed but the loss of the major part of the acid is avoided,

and the reaction mixture being kept at 250 to 300 C. at least during thelatter part of the reaction.

3. A process according to claim 2 wherein any substantial amounts ofresidual carboxylic acid are ultimately removed. 7

4. A process according to claim 1 wherein the treated carboxylic acidcontains from 10 to 26 carbon atoms in the molecule.

5. A process according to claim 2 wherein the treated carboxylic acidcontains 18 to 22 carbon atoms in the molecule.

6. A process according to claim 2 wherein the treated carboxylic acid isunsaturated and contains 18 to 22 carbon atoms in the molecule.

7. A process for preparing condensation products which comprises heatingan acid of the formula R.C0.0H where R is an unsubstituted long chainhydrocarbon radical, at a temperature of 220 to 330 C. in the presenceof a boric acid catalyst, until the reaction mixture contains at least32% by weight of unsaponifiable matter having a mean molecular weight atleast three times that of said acid, the heating being carried out undersuch conditions that water liberated during the reaction is removed fromthe reaction zone as it is formed but the loss of the major part of theacid is avoided.

8. A process for preparing condensationproducts whichcomprises heatingan acid of the formula R.C0.0H where v R is an unsubstituted long chainhydrocarbon radical, at a temperature of 220 to 330 C. in the presenceof a boric oxide catalyst, until the reaction mixture contains at least32% by weight of unsaponifiable matter having a mean molecular weight atleast three times that of said acid, the heating being carried out undersuch conditions that water liberated during the reaction is removed fromthe reaction zone as it is formed but the loss of the major part of theacid is avoided.

9. The product prepared by the process of claim 1.

10. The product prepared by the process of claim 6.

References Cited in the file of this patent UNITED STATES PATENTS1,987,559 Hintermaier Jan. 8, 1935 1,988,021 Schmidt et al Jan. 15, 19352,308,184 Lieber Jan. 12, 1943 2,395,012 Reeder Feb. 19, 1946 2,465,337Miller et al Mar. 29, 1949 2,482,761 Goebel Sept. 27, 1949 2,513,825Sorenson July 4, 1950 2,544,365 Sorenson "2 Mar. 6, 1951 2,729,658Croston et a1 Jan. 3, 1956 2,781,386 Culemeyer Feb. 12, 1957 FOREIGNPATENTS 470,498 Great Britain Aug. 16, 1937 %;:y 7414* 1;? nfli UNITEDSTATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,923 7l8February 2 1960 Johannes Donatus Von Mikusch-Buchberg ed specificationIt is hereby certified that error appears in theprint id Letters of theabove numbered patent requiring correction and that the sa Patent shouldread as corrected below.

Column l line 67 before "hydrocarbon chain" insert or unsaturated Signedand sealed this 9th day of August 1960 (SEAL) Attest:

KARL H. AXLINE ROBERT C. WATSON Commissioner of Patent:

Attesting Officer

1. A PROCESS FOR PREPARING CONDENSATION PRODUCTS WHICH COMPRISES HEATINGAN ACID OF THE FORMULA R.CO.OH WHERE R IS AN UNSUBSTITUTED LONG CHAINHYDROCARBON RADICAL, AT A TEMPERATURE OF 220 TO 330*C. IN THE PRESENCEOF A CATALYST SELECTED FROM THE GROUP CONSISTING OF BORIC ACID, BORICOXIDE, AMMONIUM PENTABORATE, TRIMETHYL BORATE, TRIETHYL BORATE, MANNITOLBORATE AND THE MIXED ANHYDRIDES OF BORIC ACID AND FATTY ACID, UNTIL THEREACTION MIXTURE CONTAINS AT LEAST 32% BY WEIGHT OF UNSAPONIFIABLEMATTER HAVING A MEANS MOLECULAR WEIGHT AT LEAST THREE TIMES THAT OF SAIDACID, THE HEATING BEING CARRIED OUT UNDER SUCH CONDITIONS THAT WATERLIBERATED DURING THE REACTION IS REMOVED FROM THE REACTION ZONE AS IT ISFORMED BUT THE LOSS OF THE MAJOR PART OF THE ACID IS AVOIDED.